An Open-Chip for Three-Dimensional Rotation and Translation of Particle Based on Dielectrophoresis

Abstract

This study developed a three-dimensional device which can manipulate a small specimen in translation and rotation in a three-dimensional space. The device is based on an open-chip device without packaging; thus, the tip of a scanning microscope. This translational, rotational, and overturning device enables optical or scanning probe microscopy to realize the three-dimensional observation of the specimen’s surface. Especially for the atomic force microscope, it helps scan the back side of the specimen, because the back side is always chemically bonded onto the substrate. This device is based on the three-dimensional dielectrophoretic theory, which applies exact solutions on the force and torque terms. Subsequently, these solutions are applied to dielectrophoretic simulation by using a finite element method (FEM) and to simulate the trapping and rotation of this particle and facilitate three-dimensional device design. Furthermore, microelectromechanical fabrication and laser processing were applied to manufacture electrodes in three-dimensional space. The trapping, rotation, shifting, and overturning of an Aspergillus niger particle were tested to demonstrate the manipulation of this device. The results reveal the rotation at 15–35 Hz had nearly constant period, and the angular velocity was proportional to the triggering frequency. Finally, according to the dielectrophoretic theory, the rotational velocities at frequency ranges of 15–35 Hz were recorded to modify the Clausius–Mossotti factor of A. niger; the results of that procedure can serve to adjust parameters for the advanced manipulation of other particles.